Freak gravitational waves could form black holes and destroy Earth

Physicists say a kind of freakish gravitational wave would be so powerful they could tangle space-time, form a black hole and destroy the Earth. But don’t worry, they probably won’t.

Most gravitational waves – ripples in the fabric of the universe caused by the motion of massive objects – are spherical. They propagate outward like ripples from a stone dropped in a pond. But when an object or particle moves at the speed of light, it creates flat, or plane-fronted, gravitational waves that move forward like a tidal wave.